Glossary

Fanning friction factor.

Fahrenheit. See Fahrenheit scale.

farad.

Federal Aviation Administration.

a collective term for the specialized connections and fittings on a pipeline. Fabrication assemblies control product flow, direct products to the proper location, aid in product separation, and facilitate maintenance operations.

pipeline construction workers responsible for welding fabrication assemblies into the line. The fabrication crew works independently of the rest of the spread.

a mask made of a rubber frame surrounding a clear, flat lens, used to seal all or a portion of a diver’s face from the underwater environment.

a type of seal in which deformation of the seal is accomplished by a plate or flat surface.

in crystallography, a crystal system in which the unit cell is in the shape of a cube. Fcc is one of the most common and simplest shapes found in crystals and minerals.

part of a bed of sedimentary rock that differs significantly from other parts of the bed.

an installation serving two or more leases, providing one or more functions such as separation, compression, dehydration, treating, gathering, or delivery.

a log generated at a computer center that identifies various sediments, or facies, raw log data, and a litho-analysis log.

an electronic register capable of expressing true throughput volume. It includes selective means for automatically applying meter factor.

a temperature scale devised by Gabriel Fahrenheit, in which 32° represents the freezing point and 212° the boiling point of water at standard sea-level pressure. Fahrenheit degrees may be converted to Celsius degrees by using the following formula: °C = 5/9 (°F–32). 

capable of compensating automatically and safely for a failure, as of a mechanism or power source.

a cumulus cloud that lies horizontally and shows little vertical development, indicating good weather conditions.

a device used to maintain or alter the direction of a rope or a chain so that it leads directly to a sheave or drum without undue friction.

a device used to maintain or alter the direction of a rope or a chain so that it leads directly to a sheave or drum without undue friction.

see parts of line.

a portable electric heater that circulates air over an electric heating element into the space to be heated.

coarse-grained, poorly sorted sedimentary rock derived from sediments deposited in alluvial fans; a type of conglomerate.

trade name of a device used to record and measure at different speeds the flow properties of plastic fluids (such as the viscosity and gel strength of drilling fluids).

a dimensionless number used to study fluid friction in pipes. The factor is equal to the pipe’s diameter times the pressure drop in the fluid caused by friction as the fluid flows through the pipe, divided by the product of the pipe’s length and the kinetic energy of the fluid per unit volume.

federal aviation requirement.

the unit of electrical capacitance. One farad is equal to the capacitance of a capacitor that has a potential difference of 1 volt between its plates when the charge of one of its plates is 1 coulomb, there being an equal and opposite charge on the other plate. See coulomb.

the amount of any substance dissolved or deposited in electrolysis is proportional to the total electric charge passed.

an oil company supervisor who controls production activities within a limited area.

to accept, as an operator, a farm-out. See farmout.

for a lessee, to agree to assign a leasehold interest to a third party, subject to stipulated conditions. See farmout.

a device in a gas distribution system that decreases the pressure of the gas flowing through a high-pressure line as the gas passes through the regulator. The regulator decreases and maintains the pressure to a low enough value to make it suitable for use in appliances in rural homes or farms.

an agreement identical to a farm-out, with the operator as the third party. The operator takes the farm-in. See farmout.

the individual or company that has a lease farmed out to it.

the individual or company that farms out a lease.

an agreement whereby the owner of a lease who does not wish to drill at the time agrees to assign the leasehold interest, or some part of it, to a third party who does wish to drill, conditional on the third party’s drilling a well within the expiration date of the primary term of the lease. The assignment may include the entire interest together with dry hole money, or partial interest or entire interest with or without an override. If an override is retained, the owner of the lease may retain an option to convert such overriding royalty retained to an agreed-upon working interest. A farmout is distinguished from a joint operating agreement by the fact that the partner farming out does not incur any of the drilling costs. The primary characteristic of a farmout is the obligation of the third party to drill one or more wells on the farmout acreage as a condition prerequisite to completion of the transfer of title to such third party.

sea ice attached to the shore. Also called coast ice.

a secondary pipeline circuit designed for quickly transferring a product sample. This arrangement enables a representative sample passing through the main pipeline to be brought quickly to the sampling equipment, which may be located some distance from the main pipeline.

that sheave on the crown block over which the fastline is reeved.

the end of the drilling line that is affixed to the drum or reel of the drawworks, so called because it travels with greater velocity than any other portion of the line. Compare deadline.

a measure of ocean depth equal to 6 feet, or 1.83 metres.

the tendency of material such as a metal to break under repeated cyclic loading at a stress considerably less than the tensile strength shown in a static test.

in metallurgy, a measure of the trait of a metal, such as steel, to withstand repeated, or cyclic, stress without failure.

a fracture starting from a nucleus where there is an abnormal concentration of cyclic stress and propagating through the metal.

a break in the earth’s crust along which rocks on one side have been displaced (upward, downward, or laterally) relative to those on the other side.

the vertical inclination of a fault’s surface, or plane, measured from a horizontal plane.

a surface along which faulting has occurred.

a subsurface hydrocarbon trap created by faulting, in which an impermeable rock layer has moved opposite the reservoir bed or where impermeable gouge has sealed the fault and stopped fluid migration.

the animals of a given region or period considered as a whole.

the principle that fossils in a stratigraphic sequence succeed one another in a definite, recognizable order.

a provision in a gas sales contract under which the seller is guaranteed that, if the buyer purchases gas within a certain area close to his or her well, that same price will be paid to the seller.

face-centered cubic.

Federal Communications Commission.

final circulating pressure.

iron.

an agency of the U.S. Department of Transportation that sets and enforces federal aviation requirements. Address: 800 Independence Avenue SW; Washington, DC 20591; 202-267-3883.

an order, or requirement, issued by the U.S. Federal Aviation Administration that gives rules and regulations that must be followed by aircraft manufacturers, airports, pilots, and anyone involved in civil aviation in the U.S.

the U.S. agency that sets standards and licenses radiotelephone and radiotelegraph stations. Address: 445 12th Street SW, Room CY-C314; Washington, DC 20554; 202-418-0500.

an independent agency (created in 1977) of the Department of Energy that has jurisdiction over oil pipelines engaged in interstate commerce. With respect to the natural gas industry, the general regulatory principles of the FERC are defined in the Natural Gas Act (NGA), and the Natural Gas Policy Act (NGPA). The FERC also has jurisdiction over wholesale interstate electric rates, hydroelectric licensing, and oil pipeline rates. Its predecessor was the Federal Power Commission (FPC). Address: 888 1st Street NE; Washington, DC 20426.

congressional act that regulates the manufacture, use, and application of pesticides.

congressional act that establishes comprehensive land use guidelines for the Bureau of Land Management (BLM) on how to manage lands under its jurisdiction.

an oil and gas lease on federal land issued under the Mineral Leasing Act. Federal leases usually provide step-scale or sliding-scale royalty; a flat discovery royalty of one-eighth may also be specified.

congressional act that was designed primarily to assure proper and timely revenue accountability from production and leasing of federal lands.

before the establishment of the U.S. Department of Energy, gas pipelines were regarded as a utility and operated under the regulation of the FPC.

an agency in the US Department of Transportation (DOT). Congress created the agency by means of the Department of Transportation Act of 1966. FRA’s purpose is to distribute and enforce rail safety regulations, administer railroad assistance programs, conduct research and development in support of improved railroad safety and national rail transportation policy, provide for the rehabilitation of the Northeast Corridor rail passenger service, and consolidate government support of rail transportation activities.

a daily government publication that publishes proposed changes in agency rules and regulations. It also includes other government actions such as presidential proclamations and a monthly notice of changes in existing rules and regulations.

an estate in real property, completely owned, which the owner can sell or devise to his or her heirs. Often a term for distinguishing private lands (fee lands) from federal or state lands.

an estate on the surface of land created when the owner separates or severs his or her mineral interests from the surface of the land.

a freehold estate on which there are no restrictions or limitations as to who may inherit.

an estate limited absolutely to a person and to his or her heirs and assigns forever, without limitation or condition.

a freehold estate in which there is a fixed line of inheritable succession limited to the issue of the body of the grantee or devisee and in which the regular and general succession of heirs at law is cut off.

an estate limited by a deed or will that conveys ownership to a person and the female heirs of his or her body. Male heirs cannot inherit the estate.

an estate limited by a deed or will that conveys ownership to a person and the male heirs of his or her body. Female heirs cannot inherit the estate.

gas from various reservoirs that is fed into a plant for processing. The content of the feed gas is analyzed to design an individual processing plan. Also called raw feed gas.

the first treating unit in which feed gas is separated into component gases, aqueous liquid, and hydrocarbon liquid for further processing. Also called feed gas reception system.

in drilling, the entrance of formation fluids into the wellbore because hydrostatic pressure is less than formation pressure.

to lower the bit continuously or intermittently by allowing the brake to disengage and the drum to turn. The feed-off rate is the speed with which the cable is unwound from the drum.

a vessel containing a charge stock or a vessel from which a stream is continuously fed for further processing.

1. in automatic control of processes, electronic information sent back from the process and compared to the desired set point. Corrective action of the controlled variable is taken if there is any deviation. If a difference exists between the set point (reference) and the actual condition (feedback), the controlling means (such as a valve) is activated to respond for correction. This arrangement of components is commonly called a closed-loop control system. 2. in an electric circuit, the return of a portion of the output current of the circuit to its input.

an automatic process by which an operation is monitored and corrective action is taken to eliminate deviations from the operating norm.

in diamond bits, the type of flow channel that directs drilling fluid across the cutting surface of the bit in which small channels called feeders direct the fluid to flow into other channels called collectors. Compare radial flow.

material other than a catalyst introduced into a plant for processing. With regard to natural gas, used as an essential component of a process for the production of a product. Use of gas as a feedstock may be required because of the chemical reaction involved, or because of the physical burning characteristics of gas compared with other fuels, such as temperature and by-products. Examples of feedstock use include fertilizer manufacture, glass manufacture, and white brick manufacture.

a group of silicate minerals that includes a wide variety of potassium, sodium, and aluminum silicates. Feldspar makes up about 60 percent of the outer 9.3 miles (15 kilometres) of the earth’s crust.

containing or largely composed of feldspar or feldspar grains.

a pipe, a coupling, or a tool threaded on the inside so that only a male connection can be joined to it. Compare male connection.

see panel diagram.

pipeline construction workers responsible for constructing temporary gates at points where a right-of-way crosses fence lines.

ferrous oxide.

Federal Energy Regulatory Commission.

provision in gas purchase contracts that allows the purchaser to reduce the price paid to the producer by an amount that FERC did not allow in the purchaser’s rate base for ultimate pass-through to the purchaser’s customer.

clause in a gas sales contract that covers what buyer and seller agree to do about price in the event of decontrol.

a decomposition process of certain organic substances, such as starch, in which a chemical change is brought about by enzymes, bacteria, or other microorganisms. Often referred to as “souring.”

highly magnetic; ferromagnetic materials react to a magnet and can themselves become magnets. See diamagnetic, paramagnetic.

a metal alloy in which iron is a major component.

a black, powdery compound of iron and oxygen (FeO) produced in petroleum operations from the oxidation of ferrous sulfide (FeS), a reaction that releases a great deal of heat. Also called iron monoxide.

a black crystalline compound of iron and sulfur (FeS) produced in petroleum operations from the reaction of hydrogen sulfide (H2S) and the iron (Fe) in steel. Also called iron sulfide.

a metallic button, usually cylindrical in shape, normally fastened to a wire rope by swaging, but sometimes by brazing.

ferrous sulfide.

field-effect transistor.

the area of wind wave development where a certain wind force prevails from the same direction for a period of time. Also the distance over which the wind blows to generate the observed waves at a given position or point.

the local change from the normal value that an electric field produces in a semiconductor’s charge-carrier region. The field effect is used in field-effect transistors.

a transistor in which the resistance of the current path from source to drain is varied (modulated) by applying a transverse electric field between grid or gate electrodes. The electric field varies the thickness of the depletion layer between the gates to reduce conductance.

Federal Insecticide, Fungicide, and Rodenticide Act.

fluid in hole; used in drilling reports.

a direct-reading device or a device with compensating elements to offset the effects of ambient temperature; used in process control to provide remote indication of temperature or the recording of temperatures; and, are simple in design and inexpensive to manufacture. Gas-filled thermometers have the greatest measurement capabilities, operate over wide temperature ranges, and have fast response to temperature changes.

a thin skin or membrane. In electronics, it is used in the manufacture of one type of resistor.

a resistor made from a thin skin or membrane (a film). Carbon film, metal film, or metallic oxide film may be used to make resistors whose resistances are very accurate, usually within 5 percent of the desired resistance.

see air cleaner filter element.

1. on a monkeyboard, one of several extensions from a board into which the derrickman places the top of the stands of drill pipe when they are set back in the derrick. See fingerboard. 2. in oil production, a fingerlike extension of reservoir fluids that protrudes into portions of the reservoir. Such fingers may bypass parts of the reservoir that contain hydrocarbons and are therefore undesirable. See fingering. 3. in a junk fishing tool, one of several projections that are created by longitudinal slots cut into the cylinder-shaped basket of the tool. When weight is applied to the tool, the areas between the slots bend inward (become fingers) and trap the junk inside the basket. See finger-type junk basket.

can show the reaction of a pipe body or the connection to forces estimated to be in a well environment.

semi-rigid, paddlelike extensions worn on the feet to increase propulsion power while swimming.

see hot work permit.

fuels derived from sources such as starch, sugar, animal fats, and vegetable oil. Popular types of first generation biofuels include biodiesel, vegetable oil, syngas, biogas, and bioalcohol.

of or pertaining to a tool whose base, face, or head does not move while it is in use.

see flare line.

a period when little or no work is going on or when only routine work is going on. In the oil industry, flat time is often used to perform tasks that need attending to but that are not critical.

part of the United States Navy, this office mainly provides climatological information for the United States Navy, Marine Corps, and other Department of Defense agencies. However, it also provides surface marine gridded climatology (SMGC) data for any interested party. Address: Officer in Charge, 151 Patton Avenue, Room 563, Asheville, NC 28801-5014; http://navy.ncdc.noaa.gov. See surface marine gridded climatology data.

on floating offshore drilling rigs using a subsea blowout preventer, a device mounted between the annular preventer and the riser adapter on the lower marine riser package (LMRP). Flex joints bend laterally to prevent excessive bending forces from being exerted on the marine riser and the LMRP and BOP components. (A bending moment is a force lateral movement creates on an object.) A flex joint typically allows 10 degrees of offset from vertical. The riser adapter can be connected to the top of the flex joint’s neck by a flange, a hub, or by welding. Compare ball joint.

1. a measure of a material’s resistance to breaking when bent. 2. A material’s ability not to be deformed under load.

a type of electronic circuit in which either of two active devices may remain conducting, with the other nonconducting, until the application of an external pulse.

see mud cap.

a device used to control the flow of gases, vapor, liquids, slurries, pastes, or solid particles.

a graphical illustration using various symbols to represent, describe, or analyze a process. Same as a schematic.

a device used to control the flow of a fluid in a system; typically used in a closed-loop system consisting of a flow set point, flow-rate feedback, and flow valve actuator.

see flow rate.

Federal Land Policy and Management Act of 1976.

see catalytic cracking.

the product of the number of turns in a coil and the magnetic flux passing through the coil.

formation; used in drilling reports.

frequency modulation.

a two-phase system, similar to an emulsion, in which the dispersed phase is a gas or air.

a form of underbalanced drilling in which a lightweight emulsion of water and a special foaming agent are circulated to drill the well. The water used to make foam is tightly bound to the foaming chemical and usually makes up a relatively small amount of the total fluid; thus, the water does not easily separate from the fluid. See mist drilling.

in underbalanced drilling with foam as a circulating medium, a measure of the effect of foaming agents and a term used to compare foams. The longer a foam’s half life is, the better.

in underbalanced drilling with foam as a circulating medium, the percentage of gas in foam at a particular depth or pressure. For example, foam with a quality of 75 percent means it is 75 percent gas and 25 percent water. The same foam deeper in the hole might have a quality of only 60 percent, because increased pressure compresses the gas. Therefore, foam quality varies with hole depth.

in underbalanced drilling with foam as a circulating medium, a measure of the amount of liquid to gas in foam under standard conditions. It is usually expressed as so many units of gas to 1 unit of water or liquid. For example, if a foam has a 100-to-1 ratio, it has 100 cubic feet of gas in 1 cubic foot of liquid.

in underbalanced drilling with foam as a circulating medium, a measure of the properties of foam, which are similar to viscosity and gel strength of drilling mud. However, no generally accepted measurements for texture in foam are currently available.

an underbalanced drilling fluid that has a gas-to-liquid ratio higher than 250 to 1 and lower than 500 to 1. (A fluid with a gas-to-liquid ratio of 250 to 1 is foam; a fluid with a gas-to-liquid ratio of 500 to 1 and higher is mist.) Because pressure at the bottom of the hole is higher than pressure near the surface, foamed mist is foam at the bit and turns into mist uphole.

a chemical that is added to a liquid such as water to create an emulsion that contains bubbles and liquid, or foam. Foam is sometimes used in underbalanced drilling. See foam drilling.

see free on board price.

1. a cloud of minute water droplets or ice crystals suspended in the air so that the cloud bottom rests on the earth’s surface, either ground or water. See advection fog, ice fog, steam fog. 2. a wide, fine spray from a nozzle.

a well-defined mass of fog.

Federal Oil and Gas Royalty Management Act of 1982.

a flexure of rock strata (e.g., an arch or a trough) produced by horizontal compression of the earth’s crust. See anticline, syncline.

metamorphic rock that has a layered look not necessarily associated with the original layering in sedimentary rock.

see cam follower.

finding of no significant impact.

see pyrite.

a check valve at the inlet end of the suction pipe of a pump that enables the pump to remain full of liquid when it is not in operation.

a unit of measure of twisting force, or torque. The amount of energy required to move 1 pound 1 foot vertically. The metric equivalent is the centimetre-kilogram, or, in SI units, the joule.

a drilling contract that is based on footage rates. See footage rates.

a fee basis in drilling contracts stipulating that payment to the drilling contractor is made according to the number of feet or metres of hole drilled.

the rock surface forming the underside of a fault when the fault plane is not vertical-that is, if the dip is less than 90°. Compare hanging wall.

single-celled, mostly microscopic animals with calcareous exoskeletons; mostly marine.

that which causes, changes, or stops the motion of a body.

in an oil and gas lease, the clause that usually contains a statement that the lease is subject to state and federal laws. It also excuses the lessee from timely performance of obligations should certain events beyond the lessee’s power to control occur. Force majeure means a force or event that cannot be anticipated or controlled.

an expression of pressure measurement in which a force, such as a pound, bears down on a given area, such as a square inch.

air blown into a furnace or other equipment by a fan or blower.

pooling of leased tracts undertaken without the willing cooperation of all the parties. Forced pooling may occur as the result of an order from a state regulatory agency, or an order sought by one or more of the parties affected.

see statutory unitization.

the lengthwise measurement of a mobile offshore drilling rig or ship.

a short length of wire rope between the anchor and chain that facilitates increased penetration.

a depositional layer on the steep seaward face of a marine delta that lies beyond the topset beds and is composed of finer sedimentary materials than the topset beds.

that part of the seashore that lies between low- and high-tide levels.

a service under the Department of Agriculture that has three major program areas: national forest administration, state and private forestry, and research. The Forest Service manages 154 national forests and 19 national grasslands, comprising 188 million acres (75.2 million hectares) in 41 states and Puerto Rico. Address: 201 14th Street SW; Washington, DC 20250; 202-205-1760.

failure to comply with conditions set in lease clauses can result in the loss of property rights by the lessee.

to use hard blows to form and shape metallic ingots into useful items.

a special drilling fluid that contains a salt or an ester of formic acid (formate), which is chemically combined with another element such as potassium or cesium. Formate fluids are very stable at high temperatures and can be made very dense (heavy) without adding weighting materials such as barite. Formate fluids are used as completion fluids because they minimize formation damage. See completion fluid, formation damage.

a bed or deposit composed throughout of substantially the same kind of rock; often a lithologic unit. Each formation is given a name, frequently as a result of the study of the formation outcrop at the surface and sometimes based on fossils found in the formation.

the horizontal limits of a formation.

the fracturing of a formation from excessive borehole pressure.

the pressure at which a formation will fracture.

the ability of the formation to withstand applied pressure. Also called formation integrity.

a test used to determine the amount of pressure required to cause a formation to fracture.

the reduction of permeability in a reservoir rock caused by the invasion of drilling fluid and treating fluids to the section adjacent to the wellbore. It is often called skin damage.

trade name for a density log.

the angle at which a formation bed inclines away from the horizontal. Dip is also used to describe the orientation of a fault.

the analysis of subsurface formation characteristics, such as lithology, porosity, permeability, and saturation, by indirect methods such as wireline well logging or by direct methods such as mud logging and core analysis.

that part of a formation exposed to the wellbore.

fluid (such as gas, oil, or water) that exists in a subsurface rock formation.

a plot of pressure versus depth that reveals the pressure at which a formation will fracture at a given depth.

the point at which a formation will crack from pressure in the wellbore.

a method of stimulating production by opening new flow channels in the rock surrounding a production well. Often called a frac job. Under extremely high hydraulic pressure, a fluid (such as distillate, diesel fuel, crude oil, dilute hydrochloric acid, water, or kerosene) is pumped downward through production tubing or drill pipe and forced out below a packer or between two packers. The pressure causes cracks to open in the formation, and the fluid penetrates the formation through the cracks. Sand grains, aluminum pellets, walnut shells, or similar materials (propping agents) are carried in suspension by the fluid into the cracks. When the pressure is released at the surface, the fracturing fluid returns to the well. The cracks partially close on the pellets, leaving channels for oil to flow around them to the well. See explosive fracturing, hydraulic fracturing.

gas initially produced from an underground reservoir.

see formation competency.

the force exerted by fluids in a formation, recorded in the hole at the level of the formation with the well shut in. Also called reservoir pressure or shut-in bottomhole pressure.

a measure of the electrical resistance of fluids in a formation.

the tendency of certain producing formations to react adversely to invading filtrates.

the ability of a formation to resist fracture from pressures created by fluids in a borehole.

see strike.

see wireline formation tester.

the gathering of pressure data and fluid samples from a formation to determine its production potential before choosing a completion method. Formation testing tools include formation testers and drill stem test tools.

the dimension between two surfaces of a rock formation, the surfaces being the top of the formation and the bottom of the formation; in well testing, formation thickness may be abbreviated as h.

the factor that is used to convert stock tank barrels of oil to reservoir barrels. It is the ratio between the space occupied by a barrel of oil containing solution gas at reservoir conditions and a barrel of dead oil at surface conditions. Also called reservoir volume factor.

1. the water originally in place in a formation. See connate water. 2. any water that resides in the pore spaces of a formation.

a simple organic acid, HCOOH, used for acidizing oilwells. It is stronger than acetic acid but much less corrosive than hydrofluoric or hydrochloric acid and is usually used for high-temperature wells.

see hydrogen cyanide.

in the direction of the bow on a ship or an offshore drilling rig.

where a p-type and n-type semiconductor are joined, the condition that occurs when the positive terminal of a battery is connected to the lead on the p-type semiconductor and the negative terminal of the battery is connected to the lead on the n-type semiconductor. Forward biasing attracts free electrons in the n-type material across the junction toward the positive terminal, and attracts holes in the p-type across the junction toward the negative terminal. A forward-biased p-n junction offers low resistance and current flows freely across it. Compare reverse bias. See n-type semiconductor, p-type semiconductor.

a common type of in situ combustion in which the combustion front moves in the same direction as the injected air. Burning is started at an injection well and moves toward production wells as air is continuously injected into the injection well. Compare reverse combustion.

the voltage across a semiconducting diode or special transistor that carries current in a forward direction.

trade name for focused electric log that investigates the flushed zone.

the remains or impressions of a plant or animal of past geological ages that have been preserved in or as rock.

containing fossils.

to become changed into a fossil.

full-opening safety valve.

to become ensnared or tangled.

a factor used in heat-transfer calculations to represent the resistance to the flow of heat caused by dirt, scale, or other contaminants in the flowing fluids.

the first casing or conductor string (generally with a diameter of 30 to 36 inches-76 to 91 centimetres) set when drilling a well from a floating offshore drilling rig. It prevents sloughing of the ocean-floor formations and is a structural support for the permanent guide base and the blowout preventers.

a rule of interpretation holding that an instrument such as an oil and gas lease must be interpreted from within the four corners of the instrument. Interpretation is made without any aid from knowledge of the circumstances under which the instrument came into being; the instrument is construed as a whole, without reference to any one part more than another.

information obtained with from seismic surveys that includes the three dimensions of depth, height, and areal extent, plus the fourth dimension of time. Four D seismic data shows changes in a reservoir as it is produced over time.

a method of obtaining seismic data using three geophones and a hydrophone within ocean bottom sensor. The system can be deployed in node-type systems or as cables. Four C seismic can reveal prospects and reservoirs that would be hidden using conventional seismic instruments.

a kelly bushing that has four steel dowels, or pins, that fit into corresponding holes in the master bushing. When the pins are engaged with the holes, the rotating master bushing also turns the kelly bushing, which then turns the kelly and the drill stem. See kelly, kelly bushing, master bushing.

a master bushing that has four holes symmetrically positioned on its outside perimeter and into which fit four corresponding steel dowels, or pins, on the kelly bushing. When the pins are engaged into the holes and the master bushing turns, the kelly bushing also turns. See kelly bushing, master bushing.

an engine in which the piston moves from top dead center to bottom dead center two times to complete a cycle of events. The crankshaft must make two complete revolutions, or 720°.

a drag bit with four blades. See bit, fishtail bit.

a device that sends (transmits) signals to various components in an electronic process control system. Such a transmitter gets its name from the number of electrical wires used to power and operate it. Two of the wires to the transmitter provide the direct current for operation (typically 24 volts) and the other two wires transmit the signal or voltage.

a section of drill pipe, casing, or tubing consisting of four joints screwed together. Compare double, single, thribble.

the name used for the working platform of the derrickman, or the monkeyboard, when it is located at a height in the derrick equal to approximately four lengths of pipe joined together. Compare double hboard, thribble board.

flowing pressure; used in drilling reports.

floating production, drilling, and system offloader.

floating production and system offloader.

Federal Railroad Administration.

fractured or fracturing; used in drilling reports.

a fluid used in the fracturing process (i.e., a method of stimulating production by opening new flow channels in the rock surrounding a production well). Under extremely high hydraulic pressure, frac fluids (such as distillate, diesel fuel, crude oil, dilute hydrochloric acid, water, or kerosene) are pumped downward through production tubing or drill pipe and forced out below a packer or between two packers. The pressure causes cracks to open in the formation, and the fluid penetrates the formation through the cracks. Sand grains, aluminum pellets, walnut shells, or similar materials (propping agents) are carried in suspension by the fluid into the cracks. When the pressure is released at the surface, the fracturing fluid returns to the well but leaves behind the propping agents to hold open the formation cracks.

see fracture gradient.

see formation fracturing.

short for fracture packing. See fracture packing.

a part of a mixture of hydrocarbons, usually defined by boiling range-for example, naphtha, gas oil, or kerosene.

a test for the composition of gas or two-phase gas-condensate streams. The analysis generally shows not only the composition in percentage of each hydrocarbon present through hexanes or heptanes but also the gallons per thousand cubic feet of liquids by component and the heating value of the gas.

the separation of crude oil into different cuts of fractions by distillation.

to separate single fractions from a mixture of hydrocarbon fluids, usually by distillation.

the vessel or tower in a gas plant in which fractionation occurs. See fractionate.

see fractionating column.

the separation of a chemical compound into its components, or fractions, by their various boiling points by heating them to a temperature at which several fractions of the compound will evaporate. See distillation, fractional distillation.

a crack or crevice in a formation, either natural or induced. See explosive fracturing, hydraulic fracturing.

a procedure by which acid is forced into a formation under pressure high enough to cause the formation to crack. The acid acts on certain kinds of rocks, usually carbonates, to increase the permeability of the formation. Also called acid fracturing. Compare matrix acidizing.

the pressure gradient (psi/foot) at which a formation accepts whole fluid from the wellbore. Also called frac gradient.

in well completion, a sand control technique that combines well fracturing, gravel packing, and a screen liner. See hydraulic fracturing, gravel packing, and screen liner.

the pressure at which a formation will break down, or fracture.

zone of naturally occurring fissures or fractures that can pose problems with lost circulation.

shortened form of formation fracturing. See formation fracturing.

a fluid, such as water, oil, or acid, used in hydraulic fracturing. The fluid carries propping agents that hold open the formation cracks after hydraulic pressure dissipates. See acid fracturing, hydraulic fracturing, propping agents.

a cloud that has a ragged appearance, as if torn. Such clouds are torn from a main cloud bank by strong winds. Also called scud.

any of the cavities in the human body that contain air and are normally connected to the atmosphere, including lungs, sinuses, and middle ear.

see butanes required.

an electron on the outer shell of an atom that moves readily from one atom to another.

a hydrocarbon that exists in the gaseous phase at reservoir pressure and temperature and remains a gas when produced under normal conditions.

a space (hole) in an atom that is not bound to an impurity in a semiconductor. A free hole is the opposite of a free electron and is a positive charge. See free electron.

the price actually charged at the producing country’s port of loading.

oxygen that exists in molecular form (O2) without being bound in a compound.

an area or point above the point at which a tubular, such as drill pipe, is stuck in the wellbore.

a type of downhole hydraulic pump that moves in and out of the well by means of circulating fluids. See hydraulic pump. Compare fixed pump.

in a container partially filled with liquid, the area of the top of the liquid. A completely filled container does not have a free surface because the liquid is not free to move about in the container as the container moves. Free surface is of particular concern on floating offshore rigs because any large and partially filled containers, such as the mud pits, or tanks, on board the rig cause the weight of the liquid in the containers to shift as the rig rolls. This shift in weight, if great enough, can create stability problems on the rig.

1. water produced with oil. It usually settles out within five minutes when the well fluids become stationary in a settling space within a vessel. Compare emulsified water. 2. the measured volume of water that is present in a container and that is not in suspension in the contained liquid at observed temperature.

the gas enters the helmet in a constant stream and flow can be controlled by the diver. The helmet constantly vents out of the exhaust so there is always positive pressure in the helmet. Because of this constant free flow, these helmets are only used in shallow water applications or in contaminated diving.

a device run on wireline into the wellbore and inside the fishing string and fish to locate the area where a fish is stuck. When the drill string is pulled and turned, the electromagnetic fields of free pipe and stuck pipe differ. The free-point indicator is able to distinguish these differences, which are registered on a metering device at the surface.

a vertical or horizontal vessel into which oil or emulsion is run to allow any water not emulsified with the oil (free water) to drop out.

the vertical distance between the waterline and the freeboard deck on a ship, boat, or floating offshore drilling rig. Draft plus freeboard equal total height of vessel.

the uppermost continuous deck on a ship or floating rig that has a permanent means of closing all openings to the sea.

of or pertaining to objects in the wellbore that do not contact the sides of the hole or the riser pipe, but which may be suspended from equipment on the surface.

see Pugh clause.

the action in which the clutch used between an auxiliary hydrodynamic brake and the drawworks drum shaft automatically disengages and runs freely while the empty block is being hoisted.

a device fitted on the vertical support members of the Trans-Alaska Pipeline System (TAPS) to circulate a refrigerant continuously between the subsoil and the top of the pipe. The refrigerant keeps the ground beneath the pipeline frozen to prevent frost heaving.

the depth in the hole at which the tubing, casing, or drill pipe is stuck. See free-point indicator.

the temperature at which a liquid becomes a solid.

the number of cycles completed by a periodic quantity in a unit time-for example, the number of complete alternations (cycles) per second of alternating electric current.

an electronic instrument for converting frequency (pulse train) to a proportionate analog signal.

an electronic device used to measure the frequency of a signal by counting the number of cycles in the signal during a predetermined time interval.

the varying (modulating) of a wave in which the instantaneous frequency of the modulated wave differs from the carrier frequency by an amount proportional to the instantaneous value of the modulating wave. Compare amplitude modulation.

an output in the form of frequency that varies as a function of the applied measurand (e.g., angular speed and flow rate).

the measured values over which a meter or other measuring instrument is intended to measure, specified by their upper and lower limits.

a Beaufort 8 wind blows from 34 to 40 knots.

1. water that has little or no salt dissolved in it. 2. underground water, generally located near the surface, that does not contain a large amount of salt and from which most underground drinking water supplies are drawn. 3. inland surface water, such as lakes, streams, and ponds, that is not salty.

see mud.

resistance to movement created when two surfaces are in contact. When friction is present, movement between the surfaces produces heat.

see journal bearing.

a spool on the side of the drawworks cathead that reels in a soft line, called the catline; used for hoisting light equipment on the rig floor.

a clutch that makes connection by sliding friction.

a dimensionless number used in the study of the flow of fluids in pipes. It is equal to the Fanning friction factor times a dimensionless constant. See Fanning friction factor.

a reduction in the pressure of a fluid caused by its motion against an enclosed surface (such as a pipe). As the fluid moves through the pipe, friction between the fluid and the pipe wall and within the fluid itself creates a pressure loss. The faster the fluid moves, the greater are the losses.

in a drum clutch, pads of friction material are squeezed against a drum attached to the driving shaft. Friction between the shoes and the drum allows the clutch to engage.

a force that slows the speed of an object as it moves. Drag occurs as an object moves through a fluid because of the friction that occurs between the object and the fluid; it also occurs as an object moves against another object.

the opposition to flow created by a fluid when it flows through a line or other container. Frictional resistance occurs within the fluid itself and it is created by the walls of the pipe or container as the fluid flows past them.

an interface between two air masses.

on a grated stair tread or a grated floor panel on an offshore installation, a steel bar that is attached to the front of the tread or floor panel.

in meteorology, a three-dimensional layer of large, horizontal pressure gradients.

movement of the soil resulting from alternate thawing and freezing. Frost heaving generates stress on vertical support members of pipelines in the Arctic and, by extension, on the pipe itself.

the phenomenon resulting when water invades rock, freezes, and, by its expansion, wedges apart the rock. Repeated freeze-thaw cycles can quickly break up any rock that has even the tiniest cracks.

said of equipment the components of which do not operate freely.

a foot of seawater. A unit of pressure at sea level generally defined as representing the pressure exerted by a foot of seawater having a specific gravity of 1.027, and is equal to approximately 0.445 pounds per square inch.

foot.

foot-pound.

feet per minute.

feet per second.

square foot.

cubic foot.

cubic feet per barrel.

cubic feet per day.

cubic feet per minute.

cubic feet per second.

a device an engine operator uses to separate water and solid materials from fuel. Centrifugal force created by the rapidly spinning centrifuge causes dirt and water, which are heavier (denser) than fuel, to move to the outside of the centrifuge where they are removed.

in improved recovery, the amount of coke available for in situ combustion, measured in pounds per cubic foot of burned area. Coke is formed by thermal cracking and distillation in the combustion zone. The amount of available coke depends on the composition of the reservoir crude oil.

a mechanical device that sprays fuel into a cylinder of an engine at the end of the compression stroke.

a hammerlike noise produced when fuel is not burned properly in a cylinder.

a device installed on a diesel engine to reduce the amount of smoke coming out of the engine’s exhaust. If the engine’s governor delivers more fuel than air to the engine, the engine smokes too much. A fuel modulator makes the governor increase the fuel supply only at the same rate as the air increase. Such rate control holds down the black smoke from the engine exhaust during acceleration or sudden loading. See governor.

1. diesel fuel. 2. heavier liquid hydrocarbons, such as bunker oil, that is used to fuel turbines on a ship or other vessel.

the pump that pressurizes fuel to the pressure used for injection. In a diesel engine the term is used to identify several different pumps: it is loosely used to describe the pump that transfers fuel from the main storage tank to the day tank; it is also used to describe the pump that supplies pressure to the fuel-injection pumps, although this is actually a booster-type pump.

any relatively small pump in an engine’s fuel system that moves fuel from one fuel tank to another or from a tank to another location in the fuel system.

see nozzle.

the support about which a lever turns.

a bottomhole assembly, usually made up of drill collars and a stabilizer just above the bit, that can be used to increase hole angle. In holes inclined 3 degrees or more off vertical, the stabilizer acts as a fulcrum; the drill collars above the fulcrum sag toward the low side of the hole, forcing the bit toward the high side and increasing hole angle.

the tendency of a fulcrum assembly to increase hole angle. See fulcrum assembly.

a logic element in an electrical circuit that operates on two binary digits and a carry digit from a preceding stage to produce as output a sum digit and a new carry digit.

in electronics, the greatest amount of electric power (the greatest load) that a circuit or device is designed to carry under specified conditions.

of a valve, fitting, or other object with an opening placed in a pipe, or line, which, when fully open, matches (or nearly matches) the diameter of the pipe in which the valve, fitting, or object is mounted.

a completion tool used in deepwater wells. When run into the hole, the valve isolates the tubing from the annulus and allows packers to be set. It has a solid metal barrier that holds pressure from above and below. This barrier may be opened without destroying it, which ensures that it will open reliably.

a bit that has maintained its original diameter.

a wellbore drilled with a full-gauge bit. Also called a true-to-gauge hole.

the displacement of a mobile offshore drilling rig or ship when floating at its deepest design draft.

a valve for the automatic release of pressure or temperature exceeding preset limits. The valve is designed to open fully upon opening rather than in increments proportional to the amount of pressure.

a trailer supported entirely by its own wheels.

the conversion to direct current of both the negative and the positive pulsations of alternating current.

the production from a well as it emerges from the mouth of the well and prior to any separation of the stream’s components.

clay or clay-like material used as a filter. See attapulgite.

a mathematical rule between two sets that assigns to each member of the first set exactly one member of the second.

see base quantity.

relating or pertaining to petroleum products with characteristics so similar that they can be mixed together, or commingled.

viscosity as measured by the Marsh funnel, based on the number of seconds it takes for 61 cubic inches (1,000 cubic centimetres) of drilling fluid to flow through the funnel.

a device used to protect electrical equipment from overload. It has a wire that melts at high temperature to open the circuit.

a thermal device employed on surface flow lines as part of an ESD.

a powdered resin coating that forms a skin over pipe when applied to its heated steel surface. Usually applied at the mill.

market in which prices are determined by open bidding for contracts on the trading floor of a commodities market such as the New York Mercantile Exchange. A futures contract is a commitment to deliver or receive a specific quantity and grade of oil or product during a designated future month at a preset price. Delivery of the physical product occurs in only a small number of cases, with most participants liquidating their positions before the end of trading.

free-water knockout.